1. Field of the Invention
The present invention relates to a method and apparatus for preparing silicone elastomer foam.
2. Background Information
The properties of silicone elastomer foams, for example, heat resistance, hydrophobicity, cold resistance, ageing resistance and electrical insulation properties, are known to be much better than those of foams made from other types of polymers such as polyolefins and polyurethanes. One method for preparing silicone elastomer foams involves the mixing of two liquid organopolysiloxanes containing functional groups that react to produce a cured elastomer and hydrogen gas. A foam is generated by the hydrogen produced during the curing reaction. Because the evolved hydrogen is very light and readily escapes, the cells formed by the hydrogen in this method are unstable, and, moreover, growth of the cells has a strong tendency to be irregular. This precludes preparation of high-expansion ratio foams with a uniform cell structure.